Prefabricated building



1944- K. L. WACHSMANN ET AL 2,355,192

PREFABRICATED BUILDING Filed May 50, 1942 7 Sheets-Sheet l K. L.WACHSMANN ET AL ,3 5,192

PREFABRICATED BUILDING Filed y 50, 194.2

7 eets-Sheet 3 1944- K. L. IVVACHSMANN ET AL ,3 5,192

7 Sheets-Sheet 5 Filed May 50, 1942 PREFABRICATED BUILDING 1944- K.WACHSMANN ETAL. 2,355,192

PREFABRICATED BUILDING Filed May 30, 1942 '7 Sheets-Sheet 6 Aug. 8, 19K. 1.. WACHSMANN ET AL 2,355,192

PREFABRIGATED BUILDING Filed May 30, 1942 7 Sheets-Sheet 7 I PatentedAug. 3, 1944 raamnmcsran normmo Konrad L. Wachsmann and Walter Groplns,Lincoln, Masa, assignors to General Panel Corporation, New York, N. Y.

Application May so, 1942, Serial No. 445,216

9 Claims.

This invention relates to buildings intended for various purposes, suchas dwellings, camps, barracks, and others.

It is the chief object of the invention to devise a building structurewhich can be assembled exclusively, or substantially so, from standardunits or sections, each consisting fundamentally of a duplicate of theother, so that they can all be manufactured completely in a factoryequipped with machinery for producing them efllciently and accuratelyand thus eliminating much of the labor customarily involved inmanufacturing parts at the site of the building. In other words, theinvention aims to transfer most of the labor involved in theconstruction of a building from the site of .the building itself to afactory and to make the erection of the building primarily one ofassembly.

To this end it is a further object of the invention to devise aconstruction which will eliminate practically all of the necessity forusing nails, screws,.hooks, and similar fastenings during such assembly,but to provide a more satisfactory means for securing the sectionstogether and to make the sections so standardized that with only minorexceptions, any frame section can be interchanged with any other.

The nature of the invention will be readily understood from thefollowing description when read in connection with the accompanyingdrawings, and the novel features will be particularly pointed out in theappended claims.

In the drawings,

Figure l is a perspective view of a standard frame unit made inaccordance with this invention;

Figs. 2 and 3 show minor variations of the frame unit illustrated inFig. 1 to adapt it for use at special points in the building;

Fig. 4 is a sectional view on the line 4-4, F 1;

Fig. 5 is an angular view of a frame of a very simple building andillustrates the fact that such a frame can be made exclusively ofstandard frame units like that illustrated in Fig. 1;

Figs. 6 and 7 are vertical and horizontal sectional views. respectively,illustrating the means provided by this invention for securing adjoiningunits rigidly to each other;

Figs. 8, 9 and 10 are perspective views showing, respectively. a wedge,a connector plate, and a cross piece forming parts of a joint structurewhich is an important feature of this invention;

Fig. 11 is a perspective view of a corner portion of a buildingassembled chiefly from parts embodying features of this invention;

Fig. 12 is a sectional view at the junction of three frame units;

Fig. 13 is a similar view at the junction of four frame units;

Fig. 14 is a horizontal, sectional view, with parts broken away, showinga ground floor arrangement of a portion of a dwelling embodying featuresof this invention; and

Figs. 15 and 16 are vertical, sectional views of parts ofa buildingembodying features of this invention.

Referring first to Figs. 1 and 4, a standard frame unit is there shown.It comprises two side pieces 2-4 connected by two end pieces 3-3. Suchconnection may be made in any convenient way. A satisfactoryconstruction is produced by securing the pieces together at the cornersof the frame by a slot and tongue joint fastened by glue, screws ornails. The stock of which these frame pieces are made naturally will bevaried to suit the requirements of different building structures, butfor smaller buildings these parts may consist of 2 x 4'5, grooved at oneinner edge as indicated at a in Fig. 4.

While this fundamental frame unit is used throughout the building andthe frames for many building structures will be composed almostexclusively of these units, some modification of them, usually in thenature of additions, will be necessary to enable them to functioneffectively for special uses. For example, Fig. 2 shows the samefundamental frame unit illustrated in Fig. 1 to which cross pieces 4 and5 and a brace 6 have been added to the upper portion thereof and similarcross pieces 4', 5' and a brace 6' have also been added at the bottom,thus making this frame suitable to receive a window. If the lower addedparts, namely, 4', 5' and 6' are eliminated, then the frame is adaptedto take a door.

Similarly in Fig. 3 the same frame unit shown in Fig. 1 is used, butcross pieces I and 8 have been secured to it to adapt it for use in thefloor. The notches provided to receive these cross pieces are indicatedat b in Fig. 1. For some buildings added cross pieces like those shownat I and 8 will be required in these floor frame sections.

These are typical of the modifications which must be made to thestandard frame unit shown in Fig. 1 in order to adapt it for use incertain parts of building structures of common forms.

Inasmuch as this invention proposes to make the building frame chiefly,and in some cases exclusively, of these frame units, it is contem-.plated that they will be rigidly ioined to each other, edge to edge,with the lengths of different units extending in three planes positionedat right angles to each other. For this purpose the standard frame shownin Fig. 1 is made of a length which is equal to. or, far more commonly.is a multiple of, its width. In the form at present preferred the lengthis equal to three times the width. And an important feature of thisinvention resides in novel means for securing these units together inany of the various relationships just mentioned.

Byreferring to Figs. 1 and 4, it will be observed that the edge of-eachlongitudinal frame piece 2 is composed of a fiat edge face c flanked bytwo bevelled surfaces 41-41. This is also true of the end pieces 3, sothat the entire edge of each unit has this same cross-sectional shapewith the two bevelled faces forming angles of 45 with both side faces ofthe frame and also with the surface c but lying at an angle of 90 toeach other. This edge construction makes it possible to join the unitstogether in any given direction, and in combinations of two, three orfour frame units, with flat surfaces abutting against other flatsurfaces as illustrated, for example, at the upper part of Fig. 11. Insome cases other building units, such as filler strips, bases, and thelike, will be used with these frame units, as shown in the part of Fig.11 just referred to.

A novel form of wedge connector or joint is provided for locking thebuilding units in this relationship and the parts of which this joint iscomposed are illustrated individually in Figs. 8, 9 and 10. They consistof a plate connector or main-stay Ill having two parallel slots near itsopposite ends, a cross piece l2, one portion of which is offsetrelatively to the other, both being slotted, and a wedge l3.

Referring to Fig. 7, it will be seen that two uprights 2-2 of adjoiningframe units are there shown positioned approximately edge to edge and inopposed relationship. Cooperating with these piecesare correspondingfiller pieces 2'-2' which are made exactly like the parts 2-2 exceptthat their width, as measured from the edge faces 0, is not as great asthat of the parts 2. Each of these four pieces is slotted transverselylat intervals, as shown at e in Figs. 1 and 4, and the slot e isintersected by another slot or mortise 1 cut into it from the edge facec.

Referring again to Fig- 7, it will be seen that the shank portions g(Fig. 10) of two cross pieces l2-I2 are inserted in the edgewise slotsf-f (Figs. 1 and 4) of the parts 2-2 in such a relationship that theiroil'set portions register one with the other. The slots in their shankportions register with the transverse slots e-e (Figs. 1 and 4) of therespective parts 2-2, and the wedges l3--l3 are driven into the latterslots and through the slots in the cross pieces, thus anchoring thelatter in their respective frame member 2-2. The shoulders formed at theoffset in each of the cross-pieces prevent the overdriving of one ofthese members when installing it in one of the building members. Next aconnector plate I0 is inserted through the registering slots of thecross pieces, one of the parts 2 is placed in position so that one endof the connector is inserted in the appropriate one of its slots 1, andthen a wedge I3 is driven through the slot in the connector, this wedgebeing positioned in the slot 0 of that particular part 2'. Then theother part 2' is placed in position in the same manner as was thecorresponding part just mentioned with the opposite 76 end of theconnector l0 inserted in the slot 1,

after which a wedge I 3 is driven into the slot e' should be observedthat each wedge has a flat back which may, however,.be corrugated asshown in Fig. 8 or otherwise roughened, and that the opposite face has athin end h, followed by a taper i, and then by anotherflat surface. Thatis, following the taper the wedge is of uniforinthickness. If the partsare made accurately it will be found that when the wedges are driven up,the building members 2-2 and 2'2' are all drawn tightly together withthe two bevelled faces of each piece abutting respectively againstcorresponding faces of two adjoining members. Thus a very secure andrigid union of the parts to each-other is produced.

Such a wedge connector can be and preferably is used throughout thestructure. Important ad-.

vantages of it are that it permits the union of the parts to each otherrapidly without the use of tools other than a hammer, does not requireskilled labor, and that it lies entirely within the frame pieces whichit connects. Inasmuch as the four arms of this joint body radiate from acommon axis, and the diagonal edge faces of all the pieces connectedtogether by it intersect at said axis, and this axis is at the center ofthe joint, the action of the wedges as they are driven into place forcesall of these wood pieces radially toward said axis until such movementis arrested by the meeting of the obliquely disposed or bevelledsurfaces of those pieces. Preferably this occurs just as the upper edgesof thetapered surfaces of the wedges are about to pass into engagementwith the solid walls of the slots in which they are located and the flatsurfaces of the wedges are about to enter the slots so that theroughened backs of the wedges will produce some deformation of thewooden parts of the building members with which they are in contact.This, of and by itself, ensures that the wedges will be firmly retainedin their locking positions against any tendency to back out. Thattendency, however, is reduced practaken apart and is again assembledwith suitable building elements. If it were practical to make the partswith sufficient accuracy, then some of these locking members, such asthose that lock the cross-pieces l2 to their respective buildingmembers, need not be wedges, although the last one of these lockingmembers driven to complete a Joint should be a wedge. It is morepractical, however, to make all of these parts alike and to use wedgesurfaces, approximately as shown, in combination with flat surfaces, soas to combine the advantages of both.

It should also be observed that the upper and lower edges of the wedgel3, Fig. 8, are each provided with notches :i and k. The former areadapted to receive hook of a tool by means of which the wedge can bewithdrawn, while the latter acts as stops to engage the face of theconthe bottom units A all lie in a horizontal plane,

nector plate or cross piece and thus to prevent over-driving of thewedge.

In addition, it will be seen from an inspection of Fig. 7 that theshoulder on each cross-piece l2 engages an edge face on the frame piece2, and that when the wedge is driven firmly into place, it pulls theshoulder of the cross-piece firmly against a flat portion of the inneredge face of the member 2, and thus locks or anchors the cross-piecesecurely to the member 2. This is true wherever One of thesecross-pieces is used, and it is of advantage in facilitating assembly orerection of a building because it permits the placing and finalfastening of these parts of the joint in their proper positions prior tobringing together the four building members and securing them in theircorrect relationship by driving the final wedges and thus locking thejoints.

From the foregoing it will be evident that this while those in theleft-hand wall B are also disposed horizontally but at right angles tothe sections A. All the other wall units C are vertically 5 disposed butthey lie in planes at right angles to invention utilizes two wedgingactions at each 2 joint, one between the individual building elementsand the respective members of the wedge connector which acts directly onthem, and the second between the bevelled surfaces of the four membersunited at the joint. IAS above stated, the movement of the four buildingmembers into mutual wedging relationship, with the bevelled surfaces ofthese pieces in abutting relationship to each other, arrests therelative inward movement of these pieces and determines when the jointis pulled up tightly. After the final wedge 13 has been driven intoplace, the parts are thereafter held in theirmutual wedgingrelationship. Both of these wedging actions are important in securingthe building members, units,,and panels in their desired cooperativerelationships. From the fact that the movements of the four membersunited at any joint are arrested in the manner just described, it willbe evident that the extreme inner edges of these parts do not alwaysabut in their final positions against the overlapped cross pieces l2, asshown in Figs. 6 and 7. Whether they do or not is immaterial, but oftenthe inner edges of two, at least, of the four members will be spacedsomewhat from the overlapped sections of the cross pieces.

In the particular arrangement illustrated in Fig. 7, the building pieces2'-2' are in the nature of fillers to cooperate with the adjoiningportions of the sections. 2-2 to make a wall of uniform thickness inwhich the joints are concealed. But the same joint constructionobviously could be used in the same manner if parts like those shown at2-2 and forming portions of additional panels were to be substituted forthe parts 2'-2'. The same joint structure also can be, and preferablyis, used wherever standard frame units can be employed in a building. InFigs. 12 and 13 the former illustrates three wall panels or sections sojoined together, while the latter shows four such wall panels orsections connected to each other, the planes of section, however, beingtaken above or below the joint structures. The material of which theconnector plate, cross pieces and wedges are made, may be metal, some ofthe synthetic plastics, or any other suitable substance.

In order to make it possible to unite these members in the differentarrangements, the frame units are so slotted as to permit the attachmentof one to another in various right-angle relationships. To this end theslots e and j, Figs. 1 and 4, for receiving each joint are so located onthe frame units that in any assembly of these parts the joints will bespaced apart by equal distances. This is well illustratedin Fig. 5 whereumn, either inside or outside 7 employed to secure They may those inwhich the units A and B are located. The top units are here shownparallel to the bot- .fitom units A, but they could as well be at rightangles to them. Considering the two sets of slots E-E in adjoiningframes in the top of the structure shown in Fig. 5, it will be observedthat they are the same distance apart as are any other two adjacent setsof slots in the building as, for example, those shown at F-F or at G-G.This 5 relationship of the slots is obtained by positioning those in theand pieces 3-3, Fig. 1, midway between the ends of these pieces,locating the upper and lower slots in each of the uprights 2 at the samedistance from the corner as are the slots 0 in the end pieces, andspacing the middle set of slots in each upright at twice this distancefrom the next adjacent set. Such a relationship is readily obtained if,for example, the frames are made three feet six inches wide and ten feetsix 5 inches long, in which event the centers of the slots nearest thecomer in the side pieces 2 will be twenty-one inches from it, the slotin each end piece 3'will be the same distance from both corners, and themiddle slot in each side piece will side. Thus with sucha constructionany frame unit can be substituted for any other in the entire structure.

Filler sections. such as those shown at 2'-2' in Fig. 7 are used atother points in the building as, for example, at the upper part of Fig.11, where they cooperate to fill out a corner. Here an additional fillerpiece l5 cooperates with the parts 2'-2'. to complete this corner. Also,in Fig. 11, and similarly in Flg.'6, a somewhat larger filler piece 2"is used in like manner to act as a base support for a partof thebuilding, and similar pieces are shown in Fig. 5 at H, I, J and K Sucha. construction may also be used in making a colthe building, and onesuch outside free standing column is illustrated in Fig. 14 at L. Othercolumns are shown in this figure at M to reinforce a large expanse ofwall.

Fig. 6 shows a joint like that illustrated in Fig. together the endframe pieces 3-3 of a horizontal floor unit and a vertical wall unit.Filler pieces 2' and 2" are here used to complete the corner, the latterbeing a base piece.

Attention is directed to the fact that at each building joint fourbuilding members or elements are secured together by the wedge connectorof that joint. The only difference between the joints is in thecharacter of these building members. be used in any combination at anyjoint because they are all shaped alike at the joint and the elements ofthe wedge connectors cooperate with all of them in the same manner. Someof them, however, extend radially away from the axis of the joint to agreater distance than others. important difference between them.

It will be understood, of course, that in setting up any building madefrom these units and the 0 panels of which they form a part, afoundation should be prepared in any suitable or customary manner tosupport the frame. Such a foundation might, for example, include piersspaced at such intervals as to provide the necessary support,

a or might consist of combinations of girders and be forty-two inchesfrom the others in the same Fundamentally, that is the most foundationwalls, either with or without such piers, as circumstances may makenecessary.

In the foregoing description reference has been made chiefly to theframe of the building, but this invention contemplates that the framealone will not be set up and then the siding, sheathing, or the like,nailed to it, but, on the contrary, that each frame unit will havepermanently secured to it those parts necessary to complete a section ofthe building. In other words, frame units which are to be used on thesite of the building will be covered externally with siding or anysuitable material and, if desired, will also be covered internally withany appropriate inside wall material. Those intended to accommodatedoors and windows will be suitably equipped for this purpose. Thosedesigned for use in the roof will be: covered with roofing, and those inthe floor with, a sub-floor and suitable top flooring.

It is the intent of this invention that, so far as practical, all of themanufacturing operations: on each panel shall be completed in a factoryso that the finished sections, each including its own frame, may beshipped to the site of the building ready for assembly into a completestructure. These standard parts can be assembled into various designs ofbuilding.

For example, in Fig. '7, portions of two adjoining wall sections arethere illustrated, each covered on both sides with matched boarding,certain of the boards being indicated at it. In Fig. 6 a similar uprightsection is shown joined to a floor section which is boarded on its lowerside, as shown at H, and at its upper side it has a sub-floor l8 and atop floor [9 secured thereto with an intervening layer 20 of buildingpaper, or the like. At its ends it may include a filler piece 2| tocompensate for the difference in thickness of the parts 2 and 3 ascompared to that of the parts I and 8 illustrated in Fig. 3. It abutsagainst the inside wall of the upright section, and

a base board 22 is secured in its usual relationship toboth the floorand the wall. This figure also shows the part 2" resting on a foundation23, and a bottom finish board or spray board 24, preferably made ofasbestos or similar material, in its usual position covering the Jointbetween the building and the foundation.

More of the parts shown in Fig. 6 are fllustrated in Fig. 11 which showsa typical corner construction of a building. Those parts hereillustrated and which are also shown in Fig. 6 are designated by thenumerals used in the latter figure.

In the wall sections it is usually preferable to cover the space in theframe with an insulation board or mattress of some such nature as thoseavailable on the market. The particular composition of the board used inany section naturally will be determined primarily by the requirementsof the building for which it is intended. Such wall board members areshown in the drawings at 25. Also, these sections can be lined at one orboth faces with building paper 26, or the like.

For convenience in wiring the building any of these wall boards can begrooved to take electric conductors. The base boards 22 shown in Figs. 6and 11 are so constructed. Also, in Fig. 11 one of the vertical insidewall boards I!" is shown provided with such grooves.

one board will be left outof' each inside wall section until after thelast wedge II has been driven. It can then be tipped into position, asindicated in dotted lines at I6a, Fig. '7, and it can be equipped with aspring clip 21 which will hold it in place. Such a board or wall elementcan, however, be pried out of position if it is desired to dismantle thebuilding, and when so removed it affords access to the wedge H which itcovers, thus permitting this wedge, and the others covered by the sameboard, to be withdrawn. The

entire building may be disassembled in thismanner, after which-the partsmay be moved to a new location and reassembled.

Additional filler pieces 28, Fig. 11, may be used at the junction of theupright sections with the filler pieces 2' to form a better closure. forthe outside joint, and they can also be used at the inner side of thewall, if desired.

While, as above stated, each section should be of a length which isequal to, or is a multiple of, its width, there are important practicaladvantages in making the sections of a length equal to three times theirwidth. Also, there is an advantage in the 3 /2 foot x 10 footdimensions, although the invention is by no means limited to these orany other dimensions. Both these advantages will readily be seen,however, from other in the manner above described. Usually '16 aninspection of Fig. 14. Assuming that'the sections are made of thedimensions just mentioned, it will be evident at once that the 3 footwidth accommodates a standard door, as indicated at 30, or a standardwindow, as shown at 3|. It is also wide enough for a hall-way, such asthat indicated at 32, or for a stair-way 33. Eight of these verticalsections can be arranged to form a '7 x 7 foot bedroom 34 adapted toaccommodate a single bed of standard dimensions at the lefthand side andleaving an equivalent amount of space in the other half of the room.Other sections associated in a manner that will be obvious from theforegoing can be made to form much larger rooms 35 and 36. In the floor,filler strips, such as those indicated at 36 in Fig. 1.4,. are, requiredbetween adjoining sections to close the spaces which otherwise would beleft at these areas. The way in which the sections may be used in a wallor roof will be evident from the foregoing in connection with theillustration in Figs. 15 and 16. Some modification of the: standardframe unit is found desirable in certain of these sections, as where thewall panel shown at the left of Fig. 15 is provided with cross piecessimilar to those shown in Fig. 2 at l and 5. Also, at the junction ofthe wall at the upper left-hand corner with the sloping roof section aspecial piece 31' is used at the end of the latter section toaccommodate the acute angle at which these sections meet.

It will thus be evident that the invention lends itself to use in themanufacture of a great variety of buildings which can either be put upfor temporary or permanent use, as may be desired. The fact that thesebuildings can be erected with practically no skilled labor and can bedismantled even more easily, is an important advantage when they are tobe used and re-used. in different locations, as in. connection withmilitary operations, migratory movements in industry, and the like.

The novel joint structure herein disclosed has been referred to above,and will be referred to in the claims, as a wedge connector, this termbeing used to designate a device which, like that above described, drawsand hold four building desire to claim as new is:

1. In a building structure, the combination of two adjoining buildingunits and a joint connecting said units and comprising two overlappingcross pieces anchored, respectively, in said units and projecting towardand disposed in an overlapping relationship to each other, said crosspieces being provided with slots in said overlapping portions, whichslots register with each other, a connector extending through saidregistering slots, each of said cross pieces having a slot near itsouter end, wedges driven through said slots and securing them in saidunits, said connector having slots in its opposite ends, and wedgessecuring said ends to additional building members to join them to saidunits in abutting relationship thereto.

2. A building joint comprising four building members each having twooblique edge faces lying at 90 to each other and positioned with thesaid faces of each in engagement with the corresponding oblique faces oftwo other members so that th planes of all of said faces intersect in acommon line, a connector intersecting said common line and having itsopposite ends anchored in two of said members positioned in opposedrelationship to each other, and two cross pieces both anchored on saidconnector and extending, respectively, into the other two opposedmembers, and wedges anchoring said cross pieces to their respectivebuilding members.

3. In a building, the combination of four building members positionededge to edge about a common axis, each of said members having bevelededges. those of each member being disposed at a 90 angle to each other,a connector plate anchored at its opposite ends in two opposed membersby transverse locking members, one of which is a wedge, two cross-piecesanchored, respectively, in the other two members and having slotted endportions overlapped one upon the other, said connector plate passingthrough both slots of said cross-pieces, and additional transverselocking members securing the outer ends of said cross-pieces to theirrespective building members, said locking members cooperating with saidconnector plate and said cross-pieces to secure all of said buildingmembers together with their beveled edges abutting one against another.

4. In a building, the combination of a series of building memberspositioned edge to edge about a common axis and a wedge connectorsecuring them in said relationship, said connector including armsradiating from said axis, said members being slotted at their inneredges to receive said arms and also slotted transversely to receivewedges, certain at least of said arms being provided with transverseshoulders positioned to bear on the inner edge faces of the respectivebuilding members in which they are positioned while said wedges bear onopposed faces of the latter members so that the intermediate portions ofthese members are clamped between the cooperating shoulders and wedges.

5. A building joint connector comprising a plate-like member slotted toprovide transverse insideedges near opposite ends thereof formingbearing surfaces for wedges, and two cross-pieces each slottedtransversely near its opposite ends, said member being adapted to passthrough two registering slots of said cross-pieces when the latter areoverlapped one upon the other with the main portions of the cross-piecesextending in opposite directions away from said overlapped areas andfrom said plate, the outer slots in said cross-pieces being adapted toreceive wedges and each of the cross-pieces having a shoulder projectingfrom its lateral surface and facing toward its respectivewedge-receiving slot but positioned close to the slot that receives saidplate-like member.

6. A building joint connector comprising a body having four armsradiating from a common axis and including a connector plate, portionsof which form two of said arms, and two crossplates forming the othertwo arms, said crossplates being releasably interlocked with the centralportion of said plate against movement away from it in a directiontransversely of the plate and all of said arms being slotted near theirouter ends to receive transverse wedges.

7. In a building, the combination of four building members positionededge to edge about a common axis, each member having bevelled edgespositioned in abutting relationship to the corresponding edges of thosemembers at opposite sides of it, and a joint connecting said members andincluding parts radiating from said axis and means anchoring saidrespective building members to said radiating parts, two of said partsslidably intersecting a third part at said axis, said means includingtransversely disposed looking members cooperating with said radiatingparts to secure said building members together with their bevelled edgeswedged together and held against movement away from said axis, one atleast of said locking members consisting of a wedge.

8. In a building, the combination of four building members positionededge to edge about a common axis, each member having bevelled edges'sides of it, and a joint connecting said members and including partsradiating from said axis and means anchoring said respective buildingmembers to said radiating parts, said parts being slidably connectedwith each other at the center of the joint, said means includingtransversely disposed locking members cooperating with said radiatingparts to secure said building members together with said bevelled edgesof each wedged between those of the adjoining members, one at least ofsaid locking members consisting of a wedge serving to draw two of saidbuilding members which are opposed to each other toward said axis andinto wedging relationship to the other two opposed building members,

9. A building having a frame structure composed chiefiy of rectangularframe units, each substantially a duplicate of the other, and wedgeconnectors securing said units together substantially throughout thestructure to form the frame for the floors, walls, ceilings, door andwindow openings, said connectors being essentially alike and eachincluding four arms radiating from a common center, one pair of saidarms being consisting of said frame units and the remainder consistingof filler pieces, said elements being slotted to receive said arms andtransverse lockin; members fastening said arms to the respectiveelements, at least one of said members being 6 a wedge.

KONRAD L. WACHSMANN.

GROPIUS.

